Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

beginning of content

Gigantism

3-minute read

Gigantism is a very rare condition that causes children to grow abnormally fast and tall. It can be treated successfully, although affected children may still experience some symptoms, and need to have regular check-ups as they grow up.

Causes of gigantism

From the time someone is born, the way their body grows is controlled by hormones produced by the pituitary gland in the brain. The most important hormone for growth is called growth hormone, also known as human growth hormone, HGH or GH.

Most children with gigantism have too much growth hormone, which makes them grow too much, too fast.

Gigantism is almost always caused by a benign tumour, also known as an adenoma, growing in the pituitary gland. Usually, there is no obvious reason for this, although it may be due to rare genetic conditions.

There are also rare genetic conditions that can cause gigantism without the child having an adenoma. Examples include Sotos syndrome, Beckwith-Wiedemann syndrome, and Weaver syndrome. You can learn more about rare genetic conditions here.

A similar condition to gigantism, known as acromegaly, can affect adults. Like gigantism, acromegaly causes abnormal growth, but instead of making the person grow tall, it causes other symptoms.

Symptoms of gigantism

Gigantism can appear in a child of any age, from baby to teenager.

The main symptom is accelerated growth, which means the child will be unusually tall for their age. Other features include:

  • large head
  • prominent forehead
  • protruding jaw
  • coarse-looking facial features, such as a broad nose
  • very large hands and feet, with thick fingers and toes
  • excessive sweating
  • a very large appetite
  • general weakness

Some people also get headaches, nausea, problems with vision and delayed puberty.

Diagnosis of gigantism

A doctor who sees a child who is growing unusually fast will need to ask some questions and do a physical examination, which might include checking height, weight, body proportions, senses, and stage of puberty.

Tests to diagnose gigantism include:

  • blood tests – to measure the level of hormones, and sometimes other substances
  • oral glucose tolerance test – to see how growth hormone levels change when blood sugar level is increased
  • an MRI or CT scan – to look at the pituitary gland
  • x-rays of the skull and jaw – to check bone thickness

It’s important to diagnose and treat gigantism as early as possible. If untreated, it can lead to problems such as diabetes, high blood pressure and arthritis.

Treatment of gigantism

Treatments for gigantism include:

  • surgery – to remove or reduce the pituitary tumour
  • radiotherapy – to reduce tumour growth and growth hormone levels
  • drug therapy – to control growth hormones levels and symptoms, and shrink the tumour

Living with gigantism

When the condition is successfully treated, children with gigantism can have a normal life expectancy and avoid most of the complications caused by it. However, they may still have symptoms such as muscle weakness and restricted movement, and some may also have psychological problems. Because of their size, it may also be hard to buy them items such as clothes and shoes. Regular medical follow-up is needed to monitor the condition over time.

More information

Last reviewed: February 2018

Need more information?

These trusted information partners have more on this topic.

Top results

Growth hormone - Better Health Channel

Some athletes and bodybuilders wrongly believe that taking synthetic growth hormone will help build up their muscles.

Read more on Better Health Channel website

Acromegaly - Lab Tests Online AU

Acromegaly is a condition in adults resulting from excess growth hormone

Read more on Lab Tests Online website

Acromegaly - Better Health Channel

Acromegaly is caused by an excess of growth hormone in adults, which causes the overgrowth of bones in the face, hands, feet and internal organs.

Read more on Better Health Channel website

Acromegaly (pituitary hormonal disorder) information | myVMC

Acromegaly is a chronic metabolic disorder caused by excessive production of growth hormone by the pituitary gland. It causes enlargement of body tissues.

Read more on myVMC – Virtual Medical Centre website

Pituitary dwarfism (growth hormone deficiency) information | myVMC

Pituitary dwarfism or panhypopituitarism is a growth hormone deficiency that causes children to be abnormally short, with otherwise normal body proportions.

Read more on myVMC – Virtual Medical Centre website

Growth hormone - Lab Tests Online AU

Why and when to get tested for growth hormone

Read more on Lab Tests Online website

Growth Hormone for Weight Loss | myVMC

Growthhormone reduces obesity through its actions on two enzymes which control fat accumulation and the breakdown of stored triglycerides into free fatty acids.

Read more on myVMC – Virtual Medical Centre website

Pituitary tumour

Generally, pituitary tumours are benign (not cancerous) and slow growing, and pituitary cancers are rare. Benign tumours don’t spread to other parts of the body, so there is no chance of secondary tumours developing. Treatment may include surgery, radiation therapy and medication.

Read more on Better Health Channel website

Pituitary disorders - Lab Tests Online AU

Site map of article content

Read more on Lab Tests Online website

Hypopituitarism information | myVMC

Hypopituitarism refers to a group of disorders which interfere with synthesis and/or secretion of hormones from the pituitary gland.

Read more on myVMC – Virtual Medical Centre website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Government of South Australia, health department logo Tasmanian government logo Government of Western Australia, health department logo